Apparatus for forming tubes



April 22, 1952 F. c. BIGGERT, JR., ET AL 2,593,835

APPARATUS FOR FORMING TUBES ll Sheets-Sheet 1 Filed April 5, 1946 NWNIIIIL INVENT R y fi ATTORNEY ATTORNEY 5 J? T. l

it an A A F F a. 1

April 22, 1952 Filed April 5, 1 946 NW MN 8 NW WW NW .W TNESSES:

April 1952 F. c. BIGGERT, JR., ET AL 2,593,835

APPARATUS FOR FORMING TUBES Filed April 5 1946 11 Sheets-Sheet swnmzsszs: INVENTORS ATTORNEY April 22, 1952 F. c. BIGGERT, JR., ET AL I2,593,835

APPARATUS FOR FORMING TUBES Filed April 5, 1946 ll Sheets-Sheet 4WTNESSES: 6 a.

y I INVENTO 5 W?% ATTORNEY April 2 1952 F. c. BIGGERT, JR., ET AL2,593,835

APPARATUS FOR FORMING TUBES Filed April 5, 1946 11 Sheets-Sheet 5WITNESSES: *5 3 INVENTOR WM 2472/ BY J ATTORNEY April 22, 1952 F. c.BIGGERTQJR" ET AL 2,593,835

APPARATUS FOR FORMING TUBES Filed April 5, 1946 ll Sheets-Sheet 6INVENTORS B}; J t l ITNESSES:

ATTORNEY April 22, 1952 I F. c. BIGGERT, JR., ET AL 2,593,835

APPARATUS FOR FORMING TUBES Filed April 5,1946 11 Sheets-Sheet 7 r x 9 Eo o ATTORNEY WITNESSES}:

April 1952 F. c. BIGGERT, JR., ET AL 2,593,835

APPARATUS FOR FORMING TUBES ll Sheets-Sheet 8 Filed April 5, 1946 mg; i

lNVENTOR-S 7W 74% ATTORNEY WITNESSES:

April 1952 F. c. BIGGERT, JR, ET AL 2,593,835

APPARATUS FOR FORMING TUBES ll Sheets-Sheet 9 Filed April 5, 1946 an HWITNESSES: j%. u d 47 INVENTORJ ATTORNEY April 1952. F. c. BIGGERT, JR.,ET AL 2,593,835

APPARATUS FOR FORMING TUBES ll Sheets-Sheet 10 Filed April 5, 1946z/mi'i BY Z ITNESSES: f

ATTORNEY April 22, 1952 F. c. BIGGERT, JR., ET AL 2,593,835

APPARATUS FOR FORMING TUBES Filed April 5, 1946 ll Sheets-Sheet llITNESSESI INVENTORS 7M %Z. ATTORNEY Patented Apr. 22, 1952 APPARATUS FORFORMINGTUBES Florence C. Bigger-t, Jr., and Howard H. Talbot,

Pittsburgh, Pa., assignors to United Engineering and'Foundry Company,Pittsburgh, Pa., a corporation of Pennsylvania ApplicationApril5,1946,1Seria1 No. 659,999,-

2' Claims.- (Cl. 144-268) Theinvention relates to the manufacture of;

tubesfrom strips of wood veneer and like mate rials having similarcharacteristics, and has particularly to do with the manufacture ofplywood tubes, with reference to which it is herein described.

A plywood tube usually consists of a plurality of superposed layers ofwood veneer whose adjacent faces are adhesively ccnnectedtoeach other.Each layer is usually formed from a single sheet of veneer of the lengthrequired for a tube and of such width that in thefinished tube there isbut a slight gap, between its adjacent edges, although sometimes asingle sheet, which, may be unitary or may consist of a series ofunitary sheets whose adjacent edges are connected to each other, iswound spirally to form a plurality of layers. Before they are arrangedintubular form, faces of the veneer sheets which contact each other in thetube are provided with a suitable thermosetting cement. Each sheet ofveneer usually consists of two sheets of thin wood glued together withtheir respective grains at 45 to each other.

Plywood tubes in which each layer is formed from a single sheet havebeen made by manually rolling each sheet of veneer edgewise andinserting it separately into a tubular sleeve or casing whose insidediameter is that of the outside diameter of the desired finished tube.When released, the first rolled sheet ,to be inserted expands, due toits inherent resiliency, in general. conformity withthe inner wall ofthe-sleeve, and each succeeding sheet similarly expands againstthe inner face 'of thenext preceding sheet, but the sheets so'inserted do notexpand to true cylindrical form. After several such sheets have beensoplaced in a sleeveqan elongate inflatable tubeis placed within the.inner veneer sheet and is expanded to press the layers ofveneeroutwardly.

tube whose Wall is thicker than that resulting from three sheets,additional sheets of veneer are applied to the interior of a three-layertube'and the expansion and thermosetting operationis repeated.

An object of this inventionis tovm'ovide a,

method of, and amachine for, forming tubes from'sheet-s of wood veneerandthelike whereby tubes having any desired number of superposed layerscan be formed in one operation and at amaterial reduction in the cost ofmanufacture.-

A further objectis to provide a machine for ..forming tubes from aplurality of sheetsof wood veneer and the like in which each sheet thatforms a layer of the tube is automatically so fedto a formingmandrelthat theadjacent edgesof' the sheet are offset angularly with relationto the adjacentedges of adjacent sheets,

A further object is to provide a machine-for forming tubes from sheets,of wood veneerand the like. upon a mandreland for applying an encasingsleeve on each tubewhile onthe mandrel.

A further object is to provide a machine for forming tubes from sheetsof woodveneer and the like which diiier in length, wall thickness anddiameter.

In the practice of this invention in-its applicability to formingplywood tubesfrom a plurality of sheets of wood veneer, the. sheets arecut to the desired length of a finished tube and-of such width that eachof a series of them will form an annulus of the tube with asmall gap,in. the nature of a joint, between their adj acent.

edges. Such a series of sheets are then .fed separately and successivelyto a rotatingmandrelon which they are wrapped in superposed layers withthe adjacent edges of adjacent sheets spaced ane thus'encased tubeisthen removed frorn themandrel, after which it isthermallytreatedtoform aplywood tube in themanner explained above,

The machine herein disclosed for, thusmaking plywood tubes includesmechanism; for feeding the desired number of veneer sheetsto; amen:-

drel to formia tube, mechanismin theforrn, oi, belt 1 wrappers for,wrapping the sheets upcn the mandrel asthey arefed to. it, and;11166113111531,

for encasing. the formed tube in a sleeve ,and {removing it from themandrel.

are a u a ly offset from, he. ke aps. 0 ach, adjacent sheet,

The invention is illustrated in theaccorrnoarrying drawings, of whichFigs. 1 and 1A taken gether constitute a somewhat diagrammatic elevationof the machinewith the sheet feeding mechanismremoved to show. the beltwwrappers which are illustrated in, their open position the It also, inludes mechanism, for automatically so controlling the feeding of, thesuccessive; sheets that the; snazgzll gaps between the, adjacent; edges;of each sheet drives of the machine being omitted from this figure; Fig.2 a right end view of the machine as seen in Fig. 1; Fig. 3 an elevationto larger scale of the tube-forming portion of the machine which isshown at the right of Fig. 1A, the central portion being omitted becauseit is a repetition of units that are illustrated; Fig. 4 a plan view ofthe machine taken substantially on the broken line IV-IV of Fig. 3; Fig.5 a transverse sectional view to enlarged scale taken on the line V-V ofFig. 3 showing a belt wrapper in its open position at the completion ofa tube-- forming operation and after a sleeve has been applied to atube; Fig. 6 a view similar to the left hand portion of Fig. 5 showingthe belt wrapper in closed position at the beginning of a tubeformingoperation; Fig. 7 a right end view of one belt wrapping unit and avertical sectional view of an adjoining unit taken on the broken lineVII-VII of Fig. 6; Fig. 3 a combined elevation and vertical centralsectional view of mech anism for applying sleeves to formed tubes andfor removing from the mandrel the tubes encased in the sleeves, thecentral portion of the mechanism being omitted; Fig. 9 a horizontalsectional view of a detail taken on the line IX--IX of Fig.

8; Fig. 10 a face view of a sleeve holder, the plane of view beingindicated by the line XX of Fig. 8; Fig. 11 a horizontal centralsectional View of the mandrel with a tube formed on it, the tube beingencased in a sleeve just prior to removing it from the mandrel; Fig. 12an elevation of timing mechanism for feeding sheets, the plane of viewbeing indicated by the line XII-XII of Fig. 4; Fig. 13 a sectionalelevation to enlarged scale taken on the line XIII-XII of Fig. 12 Fig.14 a face view of a starting finger shown in Fig. 13; Fig. 15 a faceview of a drum type selector forming a part of the timing mechanism; andFig. 16 a wiring diagram of the timing mechanism.

Having reference first to the general arrangement of the machine asshown in Figs. 1 and 1A, from which the feed table is omitted, frames land 2 form end supports for a flanged beam 3 which extends from end toend of the machine and is supported medially by a frame 4. The rear endof a forming mandrel 5 is supported in a spherical bearing in a block 6which is adjustably mounted in end frame 2. While the mandrel may be ofthe collapsible type, it is preferably non-collapsible. Below theright-hand portion of beam 3 there are a plurality of belt wrapers 1,all of which are shown in Fig. 1A in their open position, and when insuch position the forward end of the mandrel rests, as shown, upon avertically adjustable support 8 borne by intermediate frame 4. By way ofexample and not of limitation, the machine here illustrated isconstructed to form tubes up to twelve feet in length, and to that endis provided with twentyfour belt wrappers, some or all of which are usedin forming tubes of different lengths. Borne by the lower flange of beam3 there is an elongate carriage 9 which is provided at its ends withholders for engaging the ends of tube-encasing sleeves ID, the carriagebeing movable longitudinally beneath the beam by an hydraulic cylindermechanism II which is attached to the bottom of the beam.

Details of the several parts of the machine as thus briefly describedwill be explained after describing the mechanism for feeding sheets tothe mandrel, which is not shown in Fig. l.

Sheet feeder The sheet feeding mechanism is constructed to feed sheetsseparately to the mandrel and at properly timed relationship with itsrotation. The sheets are preferably so fed by cooperating belts, some ofwhich are borne by a table and others by the superstructure of themachine. The preferred construction is shown in Figs. 3, l and 5.

Supported by beam 3 there are a plurality of brackets l2 which arespaced at approximately equal intervals along the beam. As shown in Fig.5 these brackets are of general Z-shape, each having an upper horizontalleg l3 connected to the top or" beam 3, a vertical leg 44 that extendsdownwardly at one side of the beam, and a horizontal lower leg l5 bywhich the upper part of the feeding mechanism is borne. Sheets forforming tubes may be conveniently supported by an idle roller table Itwhich is mounted on the tops of the lower legs it of brackets l2. shownin Fig. 5, sheets ll are stacked in series, one series being for formingeach tube. All of the sheets are of the same length, but they diminishin width from the bottom to the top of each series, the bottom sheetbeing the outermost and the top the innermost of a formed tube. Thewidth of the sheets are so calculated that when each forms an annulus ofa tube there will be but a small gap or joint between the adjacent edgesof the sheet.

At the side of the machine below brackets i2 there is a feed table 26formed of structural members including legs 2| and top beams 22 and 23that extend longitudinally of the machine. In the normal operation ofthe machine, table 20 is positioned in front of belt wrappers l as shownin Fig. 5, but for convenient accessibility to parts of the machine atthe left of the feed table, as well as to hydraulic controls below thefloor level, the feed table is supported by rollers 24 that rest ontracks 25. By disconnecting certain drives, presently to be explained,the feed table can readily be moved to the right.

Sheets ll for forming a tube are removed one at a time from the top ofthe stacked series of them by a workman who moves them edgewise' intoengagement by a plurality of horizontal belts arranged at intervalslengthwise of the feed table. These comprise lower and upper belts 26and 21, the lower belts being supported by table 20 and the upper bybracket legs [5. Each lower belt 25 extends around an idler 28 borne bya bracket 29 which is slidably mounted on the top of a plate so attachedto the upper flange of table beam 23. Each beltmay be tightened by athreaded bolt 3! whose inner end bears against the outer edge of plate39. At its inner end each belt 26 extends around a driven roll 32, andbetween belt rolls 28 and 32 there is a plate-like shoe 33 that supportsthe lower face of the upper active strand of the belt.

Each upper belt 2'! extends around an idle roll- I er 34 that issupported by a bracket 36 attached to a plate 3i connected to the topsof bracket legs. l5. The other end of each belt El extends around adriven roll 38 attached to a driven shaft 39 which is supported bybrackets ie that are attached to and extend downwardly from an angle Hconnected to the top of bracket legs l5. The lower active strand of.belt 2'! is held downwardly by a plate-like shoe 42 attached to angles43 supported by brackets 4:2 that extend downwardly from plate 3? andangle ll. In most cases belts 26 and 2'! are arranged in pairs, belt 2'!being Asv immediately above belt 25, although in some cases they may beoffset from each other, in which event the sheets are supported beneathbelt 21 by suitable plates positioned and arranged like shoes 33.

When a workman standing in front of table 25 removes a sheet I! from thetop of the stack on roller table I he squares its right end against analignment stop in the form of a vertical plate 55 (Figs. 3 and 4)attached to the upper flanges of table beams'22 and 23 at the right endof the table. The sheet is advanced by and between belts 25 and 21,towards the mandrel and belt wrappers, but its final advance to them isdetermined by the position of a series of vertically movable dogs 5|,Figs. 3, l, 12 and 13, the construction and operation of which ishereinafter explained in the description of the timing mechanism forfeeding sheets. For the present it is sufficient to state that dogs 5iare located at the delivery end of the belts 25 and project upwardly inthe path of advance of the forward edge of a sheet until the mandrel isin such a. position that when the sheet is wrapped upon it the meetingedges of the sheet will be offset a desired angular space from theadjacent edges of the previously fed sheet. During such time as theadvance of a sheet is stopped by dogs 5I, belts 26 and 2? merely slipupon the faces of the sheet.

When dogs 5| are lowered at the proper timing interval, belts 26 and 2]feed the sheet forwardly upon anapron 52 (Fig. 5) which has a smooth orpolished upper face. Above this apron there are a plurality of feedingbelts 53 arranged at suitable spaced intervals. Each such belt extendsaround adriven roll 54 borne by a driven shaft 55 which is supported bybrackets 58 connected tothe'horizontal legs I5 of brackets I2. Beloweach driving roll 54 there is an idle roll 5! borne by bracket 59attached to the top of table beam 22. The forward end of each belt 53extends around an idle roll 65 which is supported by a U-shaped bracket5| connected at its base to a rod 62 whose upper end is slidably mountedin an angle 53 that is connected to the vertical legs I4 of brackets I2.Each rod 62 is provided with a collar 64 between which and angle 53 aspring 65 that surrounds the rod acts to urge idle roller 60 downwardly;The lower limit of this idle roll may be determined by anadjusting nut66 threaded on the upper end of rod 52 and bearing upon angle 63. Fortightening each belt 53 a turnbuckle 51 is arranged between a U-shapedbracket 68 whose legs engage driven shaft 55 and a U-shaped bracket 55whose legs engage the journal of idle roll as. The lower active strandof belt 53 is held downwardly by a plate-like shoe I5 borne by theturnbuckle 61.

i As shown in Fig. 4, shaft is for driving belts 25 is provided at itsright end with a sprocket which is engaged by a chain I6 that is drivenby a sprocket I1 attached to a shaft 78. This shaftis provided with apinion '19 which engages a pinion 85 attached to. a shaft BI which ispro-' vided with a sprocket 82 that is engaged by a chain 83 driven by asprocket 34 borne by a main drive shaft 85. At the left end of the feedtable, as shown in Fig. 3, shaft is is provided with a pinion 86 whichmeshes with a pinion 87 attached to shaft 39 that drives upper belts 27.Shaft 8I, shown at the right of Figs. 3 and 4, is provided with a secondsprocket 85 that is engaged by a chain 89 which in turn engages asprocket 95 attachedlto the. right end of shaft 55 for drivingthesupper: feedi belts; 5.3.v The main. drive; shaft 6 8.5 of themachine isdriven by amotor -9I (Figs. 3 and 4) through V-belts 92, avariable speed transmission 93 and aspeed reducer 9.4.

Belt wrapping mechanism .As has been explained, the machine includes aplurality of belt wrappers I for applying sheets to the mandrel. All ofthe several belt wrappers are constructed alike, and each isindependently movable from an open position in which the belts are freefrom the mandrel to a closed position in which they engage the mandrel.Fig. 5 shows one of the belt wrappers in its open position at theconclusion of a tube forming operation and after the tube has beenencased in a sleeve, and Fig. 6 shows a belt wrapper in its closedposition upon the mandrel at the beginning of a tube forming operation.Different diameter mandrels are used for forming tubes of differentinside diameters. By way of example and not of limitation, the machineherein shown is constructed to form tubes from four to six and a halfinches in outside diameter, the outside diameters varying according tothe wall thickness of the tubes which depends in partupon the number ofsheets used to form each tube.

The several belt wrappers are separated from each other and are borne byvertical plates I05 whose lower ends are mounted on and supported by aplatform or base IUI. Each wrapper includes a belt I52 that extendsaround a driving wheel or drum I53 which is connected to the maindriving shaft 55 of the machine. In the order in which each belt travelsfrom the drum it passes over an idler H34 mounted at the end of aswingable arm I55, an idler I05 mounted on the end of a swingable armI07, an idler I08 which is also mounted on swingable arm I01, an idlerI09 which is carried by a shaft IIll borne by plates I00, and an idlerIII which is carried by the end of a belt tightening arm II2. As shownin Fig. 6, between idlers I54 and I05 the belt is wrapped around mandrel5 during the formation of each tube.

As shown in Fig. 7, swingable arm I05 is formed of a pair of plateswhich suport a short shaft M3 on which idler I54 is mounted. This arm ispivotally mounted on a shaft IIA which is supported by vertical platesI50, and is pivotally connected to the outer end of a link II5 whoseinner end is pivotally connected to and supported by a horizontallymovable block II 5 provided at its sides with grooves formed to receivehorizontally disposed rails II'I attached to plates I55. In a similarmanner, swingable arm I0! is pivotally mounted on a shaft H8 which isborne by plates I50. The lower portion of arm I 51 is provided with anidle roller I I9 which rests upon a cam I25 formed on the top ofhorizontally reciprocable block H5.

In the position in which block I I3 is shown in Fig. 6, arm I 55 is heldfirmly in its closed mandrel-surrounding position by link II5 which thenextends vertically upward, and arm IllIis likewise held in its closedmandrel-surrounding position by roller l :9 which then rests upon theelevated portion of cam !25 at the right end of the block. When block II8 is moved to the right to the position shown in Fig. 5, link i I 5swings to a substantially horizontal position to open arm I 55, androller I I9 rides downwardly upon cam I25 to permitarm I G! to movedownwardly to its open position. The mechanism for moving block I'i6will presently be-explained- Between: the; plates 1' which .Iconstitutaarm. LIM

the lower end of an L-shaped arm I 2I is pivotally mounted on a pin I22.To the outer end of this arm there is pivotally connected 9. shoe I23,which, through arm I2I, is yieldingly urged towards the mandrel by aspring I24 that bears at its outer end upon a shoulder at the outer endof a rod I25 whose inner end is engaged by a pin I26 connected to armI31, and bears at its inner end against arm I2I through a, bushing I21.In the closed position of arm i3! shown in Fig. 6, the horizontallydisposed portion of arm I2I forms an extension of apron 52 forsupporting sheets that are fed to the mandrel.

As has been explained, belt I02 extends around a belt tightening idleroller I I I supported by arm I I2. This forms one leg of a bell cranklever that is pivotally mounted on plates I by a pin I23 and whose otherleg I23 is provided at its outer end with an idle roller I36 which isengaged by the outer end of a pressure ram I3I. In a manner presently tobe explained hydraulic pressure is applied to the inner end of ram I3!to apply tension to the belt through legs I29 and N2 of the bell cranklever. When the belt wrapper is moved to its open position shown in Fig.5, the movement of the bell crank lever is limited by the head of anadjusting screw I32 which is threaded in a bushing I33 attached toplates I'M. Screw I32 is adjusted horizontally to a position where itshead limits the movement of bell crank lever arm I2I toperrnit adequateslack in wrapper belt I02 when the belt wrapper is open.

While block H3 may be variously moved horizontally to open and closebelt wrapping arms I and IE1, this is preferably done by hydraulicmechanism. Below each block -II3 there is a cylinder I34 provided with apiston rod I35 whose outer end is connected to an upwardly extending armI318 attached to the end of the block. The

inner end of the piston rod is provided with a piston I31, to theopposite sides of which pressure fluid is supplied for moving the rod.Pressure fluid is supplied to the right end of cylinder I34 through apipe I38 and a passage IdI to move the piston to the left, and issupplied to the left end of the cylinder through a pipe I39 for movingit to the right, both of which alternately act as exhaust pipes. Belowcylinder I34 there is a cylinder I4il which receives the inner end ofplunger I3I, pressure fluid for moving the plunger outwardly beingsupplied through pipe I38 and a passage I42. Flow of pressure fluid toand from these cylinders is controlled by solenoid actuated valves, aswill presently be explained.

Summarizing the operation of each belt wrapper, when it is opened itsparts are in the position shown in Fig. 5, block H3 then being in itsright hand position to permit wrapper arm IO'I to move downwardly and tocause wrapper arm I05 to swing to the left. As shown, there is thenconsiderable slack in belt I32 to facilitate the application of a sleeveto a formed tube. To move the wrapper to its closed position pressurefluid is admitted through pipe I38 and passage ItI to cylinder I34 tomove piston I3'I to the left, and by such movement block I I6 is movedto the left to cause both arms to swing pivotally to their closedposition, arm It? being swung in a counterclockwise direction by theelevation of roller II9 which rides on inclined cam I23, and arm ")5being swung in a clockwise direction by link II5. In the closed positionof the belt wrapper mandrel 5 is firmly engaged by the belt which isproperly tensioned by plunger I3I which presses outwardly. on the lowerend of bell crank lever I29, II2 to' cause its upper end to be yielding'ly urged in a clockwise direction.

As each sheet is fed to the belt wraper its leading edge is engagedbetween the mandrel and the belt which rotates the mandrel and wraps thesheet upon it. Sheets are fed successively by the feeding mechanism intimed relationship with the mandrel so that the joints formed by themeet ing edges of each sheet will be angularly spaced from the joints ofadjacent sheets. The number of sheets wrapped upon a mandrel dependsupon the desired wall thickness of the tube.

As has been stated, the machine herein illustrated is constructed toform tubes having outside diameters of from 4 to 6 /2 inches, and, ashas been explained, the right end of mandrel 5 is supported in aspherical bearing formed in block 3 which is adjustably mounted in frame2. As shown in Fig. 2, block 6 is mounted in s1ideways 238 which extendat such angle to the vertical as properly to position mandrels ofdifferent diameters, used in forming different diameter tubes, toreceive sheets from the feeding mechanism, and also to permit themandrel to move as the wall of the tube is built up by the successivewrapping of sheets upon the mandrel. Block 3 bears upon one end of aspring 239 whose other end is supported by a rod 2m which has threadedengagement with frame 2 and is provided at its outer end with a handwheel for turning it. This rod is so adjusted that the end of a mandrelof a given size is yieldingly supported in such position that the mainbody of the mandrel will properly receive sheets fed to it.

Tube encasing and stripping mechanism After a tube has been formed on a.mandrel it is encased by a sleeve, within which it is removed from themandrel. For this purpose the machine is provided with an elongatecarriage 9 which is equipped with holders for engaging the ends of asleeve and is movable in one direction telescopically to apply thesleeve to a formed tube, and thereafter in the other direction to removethe sleeve and its encased tube from the mandrel. This mechanism isshown particularly in Figs. 1, 8, 9 and 10.

Carriage ii for moving sleeves lies below beam 3 and is provided at itsend with grooves I50 (Fig. 5) within which the lower flanges of the beamlie, the carriage being thus slidably supported by the beam. When thecarriage is at the left end of the machine, as seen in Fig.1, itsubstantially encloses a pressure fluid cylinder II which is providedwith a piston rod .I5I whose outer end is attached to a bracket I52 atthe right end of the carriage. To move the rod to the right for applyinga sleeve to a formed tube, fluid pressure is admitted to the left end ofcylinder II through a pipe I53, and, to move the carriage to the leftafter a sleeve has been applied, fluid pressure is admitted to the rightend of cylinder I I through a pipe I54. Flow through these pipes to andfrom this cylinder is controlledby solemid-actuated valves which in turnare controlled by limit switches at the ends of the intended travel ofthe carriage, as will be explained.

At its left end, carriage 9 is provided with a depending bracket I55which supports a holder, formed to engage the left end of a sleeve I0,comprising a plate I56 which is attached to bracket I55 for horizontaladjustment and a bell I51 which is pivotally suspended from plate I56 bya pin I58. The opening in the upper par-'- tube.

9 tionof bell I51 through which pin I58 extends has sufiicient clearanceto permit the bell to move in various directions in a vertical plane tocompensate for lateral movements of a casing if! as it is applied to aformed tube. A different bell I? is provided for each size of sleeve I9,there being different size sleeves depending upon the outside diameterof tubes that are being formed on the machine.

Atthe right end of carriage 9 there is a supplementary carriage I59(Figs. 5 and 8) Whose upper portion is provided with elongate flangesI98 which are grooved to receive tracks IBI that extend laterally fromthe bottom of carriage 9, the arrangement being such that supplementarycarriage I59 may be moved longitudinally upon carriage 9. This carriageis provided with a depending. bracket I62 which pivotally supports asleeve holder comprising a plate I63 mounted on bracket I62 for lateraladjustment and a holder I84 which is pivotally supported by a pin I65attached to plate I63. The forward end of holder I64 isprovided with anoutwardly flared bell I66 for telescopically receiving the end of theformed As shown in Fig. 10, the sides of holder I64 are provided withgrooves for receiving fingers I9! which are pivotally attached at I68 tothe upper end of the holder. The lower ends of these fingers areprovided with laterally extending lugs I69 which lie in openings I'IOformed at the sides of the bell portion I66 of the holder. Intermediateof their ends, fingers I61 are engaged by a spring Ill which yieldinglyurges the lower ends of the fingers inwardly, so that when a formed tubeis completely encased lugs I99 snap inwardly to engage the end of thetube for stripping it from the mandrel. To maintain the holder I94yieldingly in axial alignment with a formed tube, tension springs I12extend between the sides of the holder and the upper portion of holderplate I63, as seen in Fig. 5.

Below carriage 9 there is a screw I13 (Figs. 1 and 8) whose right end isslidably and rotatably supported by an arm I14 depending from andconnecting to bracket I52 at the end of pis- This screw has threadedengageof the screw so that the screw may be rotated,

and may be moved longitudinally a limited amount. The left end of thescrew is provided with a hand wheel II5 for rotating it to adjust theposition of carriage I59 in accordance with the len th of sleevesreuuired for different length tubes formed on the machine.

At the left end of the machine sleeves ID are arranged on a suitablerack or table which may be provided with a groove for positioning asleeve in oper alignm nt for its ends to be engaged by the sleeveholders. Provision is made for quickly moving sleeve holder I64 to theright so that a casing I0 can be moved into alignment with-it and sleeveholder I51 at the left, and for then quickly moving holder I69 to theleft to' and IE2 that are attached to the screw at the ends of thebushing. The sides of sleeve I89 are provided with trunnions I83 onwhich one end of a pair of fingers I34 are pivotally mounted. The otherends of these fingers are connected to each other by a pin I85 on whichthe outer end of a link I86 is pivotally mounted, the other end of thelink being keyed to a pin I81 which is rotatably mounted in bracket armsI88 of carriage 9. To an end of pin I81 there is keyed a crank arm I89which may be swung from its horizontal position shown in full lines inFig. 8 to its position there indicated in dotted lines. When crank armI89 is thus turned, screw I13 is moved axially to the right with theresult that supplementary carriage I59 is similarly moved to the rightto lengthen the space between sleeve holder I56 at the left and sleeveholder I94 which is carried by the supplementary carriage. This movementof the screw to the right is through link I86, which is. keyed to fixedpin I91, and fingers I84 whose ends engage sleeve I89 which is heldagainst movementon the screw by collars IBI and I82. When a casing II!is in alignment with the casing holders, arm IE9 is swung from itsdotted to its full line position to cause sleeve holder I64 to be movedto the left for engaging the ends of the sleeve by it and holder I56 atthe left end of the carriage.

When a sleeve is thus engaged by carriageS, fluid pressure is admittedto the left end of cylinder I I to move the carriage to the right, thesleeve then being in alignment with a tube formed on the mandrel. Theseveral belt wrappers I are then all in their closed position shown inFig. 6, each of the belts'then being wrapped :aroun'da formed tube.Provision is made for automatically opening the belt wrappers in seriesfrom left to right as the carriage advances, the arrangement being suchthat each belt wrapper is in its open position shown in Fig. 5 by thetime the continuously traveling carriage 9 brings the forward bell end I96 of sleeve holder I64 to the portion of the formed tube that wasengaged by the belt. For this purpose, a plurality of electrical limitswitches I (Figs. 1, 1A and 5) are borne by an angle I 9| attached tothe upper flange of beam 3, these limit switches being the same innumber as the number of belt wrappers I and being spaced at the sameinterval as the belt wrappers. Supplementary carriage I59 is providedwith an upwardly extending finger I92, which, as carriage 9 moves totheright, successively trips switches I 99, each of which is connected to asolenoidactuated valve which controls the flow of pres sure fluidthrough pipes I39 and I39 of each belt wrapping unit to cause it to bemoved from its closed to its open position.

A tube A formed on mandrel 5 from six sheets of veneer, and fullyencased in a sleeve I0 for removal from the mandrel is shown inhorizontal section in Fig. 11, which also shows mechanism at the rightend of the mandrel to facilitate the telescopic application of sleevesto formed tubes and the removal of encased tubes from the mandrel."

This mechanism comprises a stop sleeve I which is mounted on the innerend of the'mandrel and is of the same wall thickness as that of the formd tube and of such length that its outer end forms with the intendedinner ends of the tube forming sheets a small gap I99 which maybe aboutone-half inch in width. Different length stop sleeves ar provided forforming different length tubes, a longer stop sleeve being requiredsheets.

when shorter tubes are being formed. Surrounding and slidably mounted onsleeve I95 there is a gap-enclosing sleeve I91, which also varies inlength according to the length of tubes being formed, and is adapted tobe moved by a collar I98 from the position in which it is shown in Fig.11 to a position in which its inner wall closes the outside of gap I95,collar I98 being slidably mounted for longitudinal movement on the stopsleeve. The top and bottom of this collar are provided with pins I99that are engaged by the slotted ends of a forked arm 290 which has apivotal connection 29I to a bracket 292. Intermediate of its lengthforked arm 290 is pivotally connected to the outer end of a piston rod293 adapted to be moved by a fluid pressure cylinder 204 to the ends ofwhich fluid pressure may be supplied through pipes 295 and 299.

Before a sleeve I9 is applied to a formed tube A, fluid pressurecylinder 294 is actuated to cause collar I98 to move to theleft asviewed in Fig. 11, thereby to slide sleeve I91 upon sleeve I95 to suchposition that the inner wall of sleeve I91 encloses the outside of gapI99 at the inner end of the formed tube. As the sleeve is applied itsinterior surface frictionally engages the outer face of the formed tubeand tends to cause the outer layer or layers of the tube to slidetelescopically to the right. This sliding movement is resisted by theunopened belt wrappers that engage the tube, but such resistance isprogressively diminished as the belt wrappers are progressively openedto permit the sleeve to be applied. If, near the end of the applicationof a sleeve, the outer layer or layers of the formed tube should slideto the right, they abut against the end of stop sleeve I95 and areconfined against further movement by it and by gap-enclosing sleeve I91. Near the end of the application of the sleeve the forward end ofbell I66 of sleeve holder I99 abuts against the end of gap-enclosingsleeve I91 and moves it to the right to the position shown in Fig. 11,and when the latches I69 of fingers I61 borne by the casing holderregister with slots 291 that are formed in the end of stop sleeve I95the latches move inwardly under the action of spring I1I (Fig. 9) to aposition beyond the end of the formed tube. By then causing carriage 9to move to the left the formed tube is stripped from the mandrel encasedin a sleeve, latches I 99 being then in engagement with the inner end ofthe tube to strip it from the mandrel as the carriage moves to the left.When an encased tube 'has been thus removed from the mandrel, carriage 9is stopped by a limit switch in a position to unload the tube upon atable or rack, which is done by turning crank arm I89 (Fig. 8) to itsTiming mechanism for feeding sheets As explained in the description ofthe sheet feeding mechanism, the advance of each sheet to the mandrel iscontrolled by dogs shown in Figs. 3 and 4, which project upwardly in thepath of advance of the forward side of the sheet until the mandrel is insuch a position that when the sheet is wrapped upon it the meeting edgesof the sheet will be offset a desired angular space from the adjacentedges of the previously fed This mechanism will now be explained. Asshown in Figs. 4, 12 and 13, each dog BI is 12 attached to a shaft 2I5which is mounted for rocking movements at the upper end of a bracket 2I6that is supported by the feed table below the plane of advance of sheetsI1 by the cooperating lower and upper feed belts 2B and 21, the dogsbeing positioned in a vertical plane substantially at the left ordelivery ends of those belts. To each shaft 2I5 there is attached theupper end of a rocker arm 2I1 whose lower end is connected to alongitudinally reciprocable rod 2I8 whose right end is pivotallyconnected to an armature 2I9of asolenoid 229 which is positioned at theright end of the feed table, as seen in Figs. 3 and 4. A rocking lever22I, pivotally mounted at 222, is connected at its upper end to rod 2I8and at its lower end to a bar 223 which is yieldingly urged to the rightby a spring 224. This urges rod 2I8 to the left to place dogs 5I intheir elevated position in the plane of advance of the sheets. As willpresently be explained in detail, the dogs prevent the advance of eachsheet I1 by the feed belts until the mandrel is in the proper positionto receive the sheet, at which time solenoid 229 is energized to moverod 2I8 to the right to lower the dogs and permit the sheet to beadvanced by the belts. The grip of feed belts 29 and 21 upon the sheetis such that the belts slip over the faces of a sheet when its forwardmovement is blocked by dogs 5 I The timing mechanism hereindiagrammatically illustrated is arranged and adjusted for so formingtubes from six sheets of veneer that the adjacent edges or joints ofeach sheet will be angularly offset from the meeting edges of eachadjacent sheet about sixty degrees, but it may be arranged and adjustedfor forming tubes of a different number of sheets with their jointsofiset at substantially equal angular intervals, or for forming tubesfrom a large number of sheets in which Joints of outer sheets are inradial line with those of inner sheets. The mechanism includes acircuit-establishing finger which lies in the path of and is adapted tobe moved by the leading edge of each advancing sheet, a drum typeselector that is driven in coordination with the mandrel and is providedwith a plurality of angularly spaced contactors adapted successively toestablish an electrical connection with one of a series of conductors,and a dial having spaced contactors connected serially to suchconductors and provided with a contact arm which is moved during eachsheet feeding cycle to such position that a circuit can be closedthrough the rodactuating solenoid 229 to lower dogs 5I only when themandrel is in the proper angular position to have a sheet applied to it;The general construction of each of these three units of the timingmechanism will first be explained, and then the electrical circuits thatthey control.

As shown particularly in Fig. 13, a finger 225 is pivotally suspendedfrom a. block 226,. which in turn is pivotally mounted at 221 to abracket 228 that is supported by the feed table. The lower end of finger225 is positioned in the plane of advance of sheets I1 a short distancein front of dogs 5|, and its upper end is provided with a horizontal arm229 adapted upon being moved upwardly to actuate a switch 239 toestablish a circuit between two conductors which will presently beexplained, the arrangement being such that as the leading edge of asheet I 1 approaches dog 5I it moves finger 225 to the left to closeswitch 239. When dogs 5I are lowered to release a sheet, the movement ofthe sheet to the left causes finger 225 to move in a clockwisedirection, which movement causes block 226 to rotate in a clockwisedirection on its pivotal support 221. This rotary movement of the blockis yieldingly resisted by a spring 23! which acts between the right endof a rod 232 and a lug- 233 which extends downwardly from bracket 228,the left end of rod 232-being pivotally connected to block 226. Thelower end of this block is held against movement in a counterclockwisedirection beyond that shown in Fig. 13 by the end of a bolt 234 whichhas threaded engagement with lug 233 for adjustment.

Positioned one on each side of finger 225 and rigidly attached to thebottom of block 226 there are a pair of arms 235 (Figs. 13 and 14) whoselower ends project below the end of finger 225 and are normallypositioned a short distance to the left of it. As a sheet is being fed,the lower ends of arms 235 are swungto the left of their 'full lineposition shown in Fig. 13 and ride upon the top of the sheet. Thiscauses block 225 to turn in a clockwise direction to elevate the lowerend of finger 225 substantially above the top of the sheets with suchclearance therefrom that finger 225 can return to a position tointerrupt the circuit previously established through switch 230 andthereby prevent a recurring tripping of dogs through the same timingcircuit prior to the complete passage of a sheet I1. When the trailingend of a sheet passes beyond arms 235, block 226 swings in acounter-clockwise direction under the action of spring 23l to place theparts as shown in full lines.

As shown in the wiring diagram of Fig. 16, the movement of finger 225 tothe left causes switch 230 to close a circuit between a conductor 240and a conductor 2M, the former being connected to a supply lineconductor 242 and the latter-extending to the drum type selector 243mentioned above and which is shown somewhat diagrammatically in Fig. 15.The selector includes a central hub 244 that is rotated by a belt 245which engages a pulley 246 attached to the hub and is driven by themandrel, Fig. 11, the arrangement shown being such that each completerevolution of the mandrel rotates the hub through a complete revolution.The hub is provided with a continuous ring 241 of conducting materialwhich is continuously engaged by a spring contact finger 248 that iselectrically connected to conductor 24!. Hub 244 is also provided with aseries of rings 249 and 249i; through 2496 formed of insulation and areprovided, respectively, with electric contact studs 250 and 256a through2520. The inner ends of these-studs are electrically connected to a con=tact sleeve 25! which is also electrically con nected to contact ring241 and extends continuously within the several rings of insulation.Positioned to make contact with the outer ends of the studs successivelythere are a series of spring contactors 252 and 252a through 2526 whichare electrically connected respectively to a series of conductors 253and 253a through 253:: which lead to the above mentioned dialcontactors.

In the position. of the parts of selector 243 shown in Fig. 15, acircuit is established between conductors 24! and 253, the circuit beingthrough conductor 24 1, contact finger 248, contacting ring 241, contactsleeve 251, stud 250, and contact finger 252 to conductor 253. Studs25!], 250a, etc. are spaced upon the drum at successive angularintervals, of about sixty degrees so that as drum 244 is rotated thestuds successively come vided with a series of equally spaced contactors251 and 251a through 251e to which the ends of the conductors 253 and253a through 253e, respectively, are electrically connected. The otherhalf of disk 256 is provided with a second series of equally spacedcontactors 258 and 2580 through 258e which are electrically connected toconductors 259 and 259a through 2592, respectively, the outer ends ofsuch conductors terminating in a single conductor 260. Rotatablymountedat the center of disk 256 there is a ratchet 261 to which anelectrically conducting arm 262 is attached. As shown in Fig. 16 one endof this arm is in contact with contactor 251 which is electricallyconnected to conductor 253, and the other end of the arm is in contactwith the contactor 258 which is electrically connected to conductor 259.A pawl and ratchet mechanism is provided for intermittently turning arm262 in a clockwise direction so that it will successively establish anelectrical connection between conductors 253a through 2153c andconductors 25912 through 259e, respectively. For this purpose a pawl 263is spring pressed into engagement with ratchet 26I and is connected tothe end of a pivoted arm 264 which is moved to the left as seen in Fig.16' by a spring 265., For retracting arm 264, it is connected to anarmature 266 of a solenoid 261 which is energized in a manner presentlyto be explained.

In the operation of the timing mechanism for feeding sheets of veneer,the forward edge of a sheet 11 trips finger 225 to close switch 230which establishes electrical connection between conductors 249 and 241,the former of which is connected to line wire 242 and the latter ofwhich extends through a retarding relay 216 to contact ring 241 ofselector 243. Contact finger 225 lies a short distance in front of dogs5| which, after switch 230 has been thus closed by a sheet 11, engagethe forward edge of the sheet and prevent its advance until the dogs arelowered. Assuming that drum 244 of selector 243 is in the position shownin Fig. 15 and that arm 262 of contact dial 255 is in the position shownin Fig. 16, a circuit is then closed through relay 210, the circuitbeing from line wire 242 through conductors 249-and 24!, contact finger248 of selector 243, ring 241, sleeve 25l, stud 250. contact finger 252,conductor 253, dial contactor 251, arm 262, dial contactor 258, andconductors 259 and 260 to the second line wire 21I The closing of thiscircuit causes relay 210 to close a circuit through a conductor 212,which is connected to line wire 21!, and a conductor 213 which extendsthrough the coil of solenoid 220 to a conductor 214 that is connected toline wire 242. The closing of this circuit causes the dog-actuating rod218 to move to the right to lower the dogs to permit feed belts 26 and21 (Fig. 5) to feed the sheet forwardly to the mandrel. Near the end ofthis movement of rod 2l6, rocking lever 22! (Fig. 12), to which one endof bar 223 is connected, causes the other end of the bar to engage andclose a switch 215 which .direction on its pivot shaft H8.

15 closes a circuit through the coil of solenoid 261 for retracting pawlarm 264, such circuit extending from line wire 242 through conductor214, switch 215, and conductors 216 and 259 to line wire 2'.

Due to the continuous rotation of drum 244 of selector 2 53 by mandrelduring a tube forming operation, each circuit established throughselector 243 is of short duration but is of sufiicient length to actuateretarding relay 2'51} which maintains the circuit through solenoid 22%for a sufiicient length of time to move dog-actuating rod 258, and alsomaintains the circuit through solenoid ZB'I for a sufficient length oftime to retract pawl arm 2M. At the end of the delayed action of theretarding relay all of the circuits are open and spring 265 moves pawlarm 264 to the left to turn contact arm 252 of contact dial 255m aclockwise direction so that its ends then establish electricalcontinuity between dial contactors 25M and 259a. When stud 259a ofselector 243 is thereafter contacted by contact finger 252a the severalcircuits just explained will again be closed. Ihus the timing mechanismfor feeding sheets assures their being so app-lied to the mandrel thatthe adjacent joint-forming edges of each are properly offset angularlywith relation to the like meeting edges of adjacent sheets.

Operation In describing the operation of the machine it will be assumedas the starting point that mandrel 5 is engaged by all of the belts I92of the belt wrappers l in the manner shown in Fig. 6, and that a casinII) has been engaged at its ends by holders It and I54 at the oppositeends of elongate carriage '9, as shown in Figs. 1 and 8. The beltwrappers are moved to their closed position shown in Fig. 6 by thesimultaneous operation of solenoid-actuated valves which control theflow of pressure fluid through pipes I33 and I39 to and from cylindersI3 and hill of each belt wrapper. Flow of pressure to the right end ofcylinder I34 causes the cam block lid of each belt wrapper to move tothe left to the position shown in Fig. 6, during which movement link II5 causes wrapper arm N to swing in a clockwise direction on its pivotshaft H4, and cam I29 causes arm It? to swing in a counterclockwiseAlso, the admission of pressure fluid through passage I42 to cylinderI48 causes ram I3I to move outwardly and press against the lower end ofarm I29 which moves arm IIZ in a clockwise direction to apply therequisite tension to each belt I02 when wrapped on the mandrel. Forengaging a casing position shown in Fig. 8 to cause casing holder I64 atthe right end of the carriage to move to the right to such extent thatthe ends of the casing may be brought into alignment with the holders.Thereafter, crank arm I89 is moved from its dotted to its full lineposition to cause the holders to engage the ends of the casing.

A workman standing at the right side of feed table as seen in Fig. 5,removes sheets ll of veneer one at a time from the several series ofthem that rest on roller table I 6, squares the end of each sheetagainst gauge plate at the right of the feed table, as seen in Figs. 3and 4, and then moves the sheet forwardly into engagement with the lowerand upper feed belts 26 and 21 which carry the sheet towards themandrel. The leading edge of each sheet is engaged by dogs 5I (Figs. 3and 4) which prevent further advance movement of the sheet until thedogs are lowered by the timing mechanism whose construction andoperation has just been explained. with particular reference to Figs.12-16. Concerning the operation of the timing mechanism it is sulficienthere to state that each sheet is released by dogs 5i in suchrelationship with the rotation of mandrel 5 that when wrapped upon themandrel the adjacent edges of the sheet are spaced angularly on themandrel a desired interval with relation to the adjacent edges of eachadjacent sheet.

When dogs 5i have been lowered, the sheet engaged by them is fedforwardly upon apron 52 (Fig. 5) by feed belts F5 and 27, and is alsofed forwardly by feed belts 53 that are positioned above apron 52. Whenthe leading edge of a sheet reaches mandrel 5 it is engaged by each beltI92 of the several belt wrappers 'i and wrapped around the mandrel bythe belts which are then driven to rotate the mandrel.

When the required number of sheets to form a tube have been thus appliedto the mandrel, the rotation of drive shaft 35 is stopped to interruptthe driving of the several wrapping belts I532, which stops the rotationof the mandrel 5. Fluid pressure is then admitted through pipe I53 tothe left of cylinder I I (Fig. 1) to cause carriage 9 to move to theright telescopically to apply casing IE] to the formed tube. As thecarriage is thus moved, finger I92 carried by supplementary carriage I59successively trips electric limit switches I96 (Fig. 5) which are borneby beam 3 as shown in Fig. 1. Each of these switches actuates a solenoidvalve which controls flow of pressure fluid through pipes I38 and I39 ofeach belt wrapping unit. Thus, as the right end of easing It approacheseach belt wrapper it is opened to permit the casing to be applied to theportion of the formed tube that was previously engaged by the belt,there then being sufficient slack in the belt, as shown in Fig. 5, topermit the application of the casing. The opening of the belt wrapperscontinues progressively from left to right as seen in Fig. 1 until thecasing is fully applied to the formed tube. When the easing is soapplied, the lower ends of fingers I61 that are carried by holder I64move toward each other under the action of spring I'II (Fig. 10) tocause latches IE9 at the ends of the fingers to move through openingsIll! at a position beyond the end of the formed tube, as shown in Fig.11. Thereafter, pressure fluid is admitted to the right end of cylinderII through pipe I54 (Fig. 1) to cause carriage 9 to move to the left tostrip the formed tube from the mandrel encased in the sleeve. This cycleof operation is repeated for the formation of each tube.

The wall thickness of each tube depends upon the number of sheets orlayers of veneer of a particular thickness that are applied to themandrel. For making tubes of diiferent interior diameters, mandreis ofdifferent diameters are used, the position of the end of each sizedmandrel that is supported by end frame 2 (Fig. 1) being so adjusted byscrew 2!!! (Fig. 2) that the mandrel will be in the proper position toreceive the veneer, shown in Fig. 6. The encased tube shown in Fig. 11is the longest that can be formed by the use of all of the belt wrappingunits '7. In making shorter tubes, belt wrappers at the right end of theseries of them shown in Fig. 1 are maintained continuously in their openposition shown in Fig. 5, the'number thus 17 maintained in open positiondepending upon the length of the tube desired to be formed. Also, inmaking shorter tubes, longer stop sleeves I95 and gap-closing sleevesI91 are used, the length of these sleeves being inversely proportionalto the lengths of tubes being formed.

According to the provisions of the patent statutes, we have explainedthe principle and mode of operation of our invention and haveillustrated and described the construction and operation of the machinethat we now consider to be the best embodiment. However, we desire tohave it understood that, within the scope of the appended claims, theinvention may be practiced otherwise than specifically illustrated anddescribed.

We claim:

1. A machine for forming tubes from sheets of wood veneer and the like,comprising a rotatable mandrel, a feeder having a plurality of upper andlower conveyor belts for engaging opposite faces of sheets and feedingthem in sequence toward and to the mandrel, belts for rotating saidmandrel and for wrapping the sheets in superposed layers upon it to forma tube, dogs located at the delivery end of said conveyor belts andmovable to a position to engage each sheet and thereby to stop itsmovement toward said mandrel, and means coordinated with the rotation ofthe mandrel to move said dogs from sheetengaging position.

2. A machine for forming tubes from sheets of wood veneer and the like,comprising a rotatable mandrel, a feeder having a plurality of upper andlower conveyor belts for engaging op- FLORENCE C. BIGGERT, JR. HOWARD H.TALBOT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 54,809 Zistel May 15, 1866341,866 Allgire May 18, 1886 373,655 Granger Nov. 22, 1887 497,299Brigham May 16, 1893 586,359 Holt July 13, 1897 625,409 Neubecker May23, 1899 1,299,031 Reynolds Apr. 1, 1919 1,734,272 Pointer Nov. 5, 19292,000,544 Winchell May 7,, 1935 2,031,570 Muller Feb. 18, 1936 2,043,026Arnold June 2, 1936 2,290,762 Miller July 21, 1942 2,392,194 SeymourJan. 1, 1946 2,402,038 Goldman et al. June 11, 1946

